Chilling audio transmissions from the moments before a Boston-bound medical plane vanished off the coast of Nantucket Saturday reveals a panicked exchange between the pilot and air traffic controllers. 

The Gulfstream G100 left Bermuda Saturday at 12:41 a.m. and plummeted more than 10,000 feet before losing contact with the Federal Aviation Administration at around 1:20 a.m., when the agency issued a Search and Rescue Alert notice, a spokesperson told The Post.

The pilot of the doomed aircraft, which was carrying six people, declared an emergency at 12:46 a.m., according to a copy of the radio transmission obtained by LiveATC.net.

“You’re coming in blind. Is that what you said?” the air traffic controller asked, seemingly struggling to understand the pilot.

The pilot’s response was inaudible. 

“You’re coming in a little weak so I didn’t hear what your response was, if you were declaring an emergency or not,” the controller said — and confirmed that the pilot was declaring an emergency. 

The controller was later heard asking the pilot of a separate plane if the medical aircraft was visible on its anti-collision system, and the pilot said it was not. 

A Massport Fire Rescue dispatcher asked emergency crews at 1:12 a.m. to get ready for a plane with an “electrical issue” to land at Logan International Airport in about 15 minutes, according to radio audio captured by Broadcastify and reviewed by The Boston Globe. 

“The aircraft has lost radio and radar,” the dispatcher said.

The plane never arrived at the airport and the fire crews’ response was called off at 1:36 a.m., according to radio transmission. 

Four Canadians – two medical personnel and two pilots – and two Bermuda natives – a patient and their relative – were onboard the aircraft, Latitude Air Ambulance, the company operating the flight, told The Canadian Press.

The US Coast Guard identifies victims or missing people 24 hours after next of kin are notified, according to an agency spokesperson.

The rescue mission’s search area is 13 nautical miles off the coast of Nantucket and extends 30 nautical miles wide and 20 nautical miles long, the military branch said.

“The FAA is coordinating with the Rescue Coordination Center and the US Coast Guard to locate the aircraft,” they said. 

Massachusetts Gov. Maura Healey said at a rally in Dorchester that the state will do “whatever it takes” to support the Coast Guard. 

David Burt, premier of Bermuda, offered condolences and promised assistance in the search and rescue efforts.

“My thoughts are with everyone on board and their families during this deeply worrying time,” he said in a statement.

“We are praying that all six people will be found safe, and we thank the search and rescue crews for their continuing efforts.”